34th Annual Scientific Meeting proceedings

Objectives:

Extreme brachycephalic breeds are more prone to developing Brachycephalic Obstructive Airway Syndrome (BOAS) and laryngeal alterations, depending on severity. BOAS is classified into four degrees based on the syndrome's components, and its clinical presentation is progressive. Chronic airway obstruction can result in laryngeal collapse (LC), which is classified into three degrees of severity. The objective of this study was to analyze the cuneiform process of the arytenoid cartilage in brachycephalic dogs through histopathological evaluation and to correlate the histopathological characteristics with BOAS severity and laryngeal collapse degree.

Methods:

Arytenoid cartilage samples were obtained from 25 brachycephalic dogs affected by laryngeal collapse and subjected to unilateral or bilateral cuneiformectomy between 2021 and 2023. Each cartilage sample underwent two histopathological evaluations: morphological (hematoxylin and eosin staining) and metachromatic (toluidine blue staining). From these evaluations, a morphological score, a metachromatic score, and a final score were determined.

Results:

Degenerative changes in the arytenoid cartilage were observed in all analyzed tissues. Degeneration was noted to varying degrees but was present across all levels of BOAS and LC severity. Most of the cartilages were classified as mildly (48%) or moderately (44%) degenerated. No significant correlation (p>0.05) was observed between degeneration scores and the severity levels of BOAS and LC.

Conclusions:

Brachycephalic dogs affected by BOAS and laryngeal collapse suffer from chondromalacia. These alterations do not appear to correlate with the degrees of brachycephalic syndrome or the severity of laryngeal collapse.

FINANCIAL SUPPORT: São Paulo Research Foundation 2023/08910-8